NEW YORK (Bloomberg) — A lawyer for American International Group sought to assail the credibility of former chief executive officer Maurice (Hank) Greenberg at a trial over whether his private company looted $4.3 billion from AIG.

Attorney Ted Wells yesterday tried to show Greenberg, 84, lied earlier in federal court in New York about how his Starr International Co., or SICO, ran a deferred-compensation plan for top AIG workers and how it ended after his ouster in March 2005.

Wells questioned Greenberg about minutes of a May 2005 meeting that said SICO ended the retirement plan by "mutual agreement" of AIG, the New York-based insurer. Wells contends SICO, then based in Bermuda, unilaterally ended the plan out of spite after Greenberg's ouster amid an accounting scandal.

"Is it the truth that the reference to a mutual agreement between SICO and AIG is a false statement?" Wells asked Greenberg in his fifth day of testimony. "Not to my knowledge, it's not," Greenberg said.

Wells went through a series of documents that he said showed that SICO didn't reach the agreement in consultation with AIG. Greenberg acknowledged that he didn't speak with his successor, former CEO Martin Sullivan, or with his replacement as chairman, former director Frank Zarb.

Greenberg said an AIG executive at the time, Robert Sandler, was a SICO voting shareholder who told him the company wanted to end the plan. Wells asked Greenberg why he never mentioned Sandler's advice in his pre-trial deposition in 2006.

Starr held 290 million shares to back a series of deferred-compensation plans that SICO renewed every two years.

Greenberg had testified that SICO funded the AIG plan through the "generosity" of the company's shareholders, and those benefits could be revoked at any time. The deferred compensation plan, he said, was held by a charitable trust and no documents required an obligation to AIG.

Greenberg also had testified that an attorney hired by AIG's independent directors advised him in January 2005 to separate SICO from AIG for corporate governance reasons. The lawyer, Richard Beattie of Simpson Thatcher & Bartlett LLP, gave him the advice at a dinner at the St. Regis Hotel in New York, Greenberg said last week. In a telephone conference outside the jury's presence, Beattie denied Greenberg's account.

"Isn't it a fact that you made up Mr. Beattie's statement?" Wells asked Greenberg.

"That's not correct," Greenberg said. "That's absolutely incorrect."

Wells questioned Greenberg for a second time after SICO attorney David Boies asked him about the retirement plan and speeches he gave to AIG employees about it. In several speeches, Greenberg said a trust existed for the employees.

"We used the term trust sometimes very loosely," Greenberg said about a 1989 speech. "I was speaking extemporaneously. Sometimes it didn't come out the way it was supposed to come out."

He said repeatedly that SICO was a charitable trust that could be dissolved at any time. He also said that SICO would terminate the deferred-compensation plan if AIG insisted that it be reported on its financial statements.

Jurors will weigh whether SICO improperly converted, or took, AIG shares after Greenberg's ouster. US District Judge Jed Rakoff will decide if SICO breached its fiduciary duty.